Clarke, Michelle J.

This paper reviews a case of metastatic 1p/19q codeleted oligodendrioglioma causing diffuse osteosclerosis and pain. Primary central nervous system (CNS) tumors rarely metastasize outside the CNS, and metastatic oligodendroglioma is rarer still. The patient in this study had relief of pain after being treated with temozolomide. We discuss this rare presentation and potential treatment options, and review the literature in regards to metastatic oligodendrogliomas.

OBJECTIVESpinal epidural arteriovenous fistulas (SEDAVFs) constitute a rare but treatable cause of vascular myelopathy and are a different subtype from the more common Type I spinal dural AVFs. The purpose of this study was to review a consecutive series of SEDAVFs from a single institution and report on the clinical presentations, functional status, and treatment outcomes.METHODSThe authors identified all SEDAVFs treated at their institution from 2005 to 2015. SEDAVFs were defined as spinal AVFs in which the fistulous connection occurred in the epidural venous plexus. The clinical presentation, functional status, immediate treatment outcomes, and long-term neurological outcomes were analyzed.RESULTSTwenty-four patients with SEDAVFs were included in this study. The patients' mean age at presentation was 66.9 years. The most common presenting symptoms were pain and numbness (22 patients, 91.7%), followed by lower-extremity weakness (21 patients, 87.5%). The mean duration of symptoms prior to diagnosis was 11.8 months. Eighteen patients (75.0%) were treated with endovascular therapy alone, 4 (16.7) with surgery, and 2 (8.3%) with a combination of techniques. There was 1 major treatment-related complication (4.2%). Fifteen patients (62.5%) had improvement in disability, and 12 patients (54.5%) had improvement in sensory symptoms.CONCLUSIONSSEDAVFs often present with lower-extremity motor dysfunction and sensory symptoms. With the availability of newer liquid embolic agents, these lesions can be effectively treated with endovascular techniques. Surgery is also effective at treating these lesions, especially in situations where endovascular embolization fails or is not safe and in patients presenting with mass effect from compressive varices.

OBJECTIVE Historically, performing neurosurgery with the patient in the sitting position offered advantages such as improved visualization and gravity-assisted retraction. However, this position fell out of favor at many centers due to the perceived risk of venous air embolism (VAE) and other position-related complications. Some neurosurgical centers continue to perform sitting-position cases in select patients, often using modern monitoring techniques that may improve procedural safety. Therefore, this paper reports the risks associated with neurosurgical procedures performed in the sitting position in a modern series. METHODS The authors reviewed the anesthesia records for instances of clinically significant VAE and other complications for all neurosurgical procedures performed in the sitting position between January 1, 2000, and October 8, 2013. In addition, a prospectively maintained morbidity and mortality log of these procedures was reviewed for instances of subdural or intracerebral hemorrhage, tension pneumocephalus, and quadriplegia. Both overall and specific complication rates were calculated in relation to the specific type of procedure. RESULTS In a series of 1792 procedures, the overall complication rate related to the sitting position was 1.45%, which included clinically significant VAE, tension pneumocephalus, and subdural hemorrhage. The rate of any detected VAE was 4.7%, but the rate of VAE requiring clinical intervention was 1.06%. The risk of clinically significant VAE was highest in patients undergoing suboccipital craniotomy/craniectomy with a rate of 2.7% and an odds ratio (OR) of 2.8 relative to deep brain stimulator cases (95% confidence interval [CI] 1.2–70, p = 0.04). Sitting cervical spine cases had a comparatively lower complication rate of 0.7% and an OR of 0.28 as compared with all cranial procedures (95% CI 0.12–0.67, p < 0.01). Sitting cervical cases were further subdivided into extradural and intradural procedures. The rate of complications in intradural cases was significantly higher (OR 7.3, 95% CI 1.4–39, p = 0.02) than for extradural cases. The risk of VAE in intradural spine procedures did not differ significantly from sitting suboccipital craniotomy/craniectomy cases (OR 0.69, 95% CI 0.09–5.4, p = 0.7). Two cases (0.1%) had to be aborted intraoperatively due to complications. There were no instances of intraoperative deaths, although there was a single death within 30 days of surgery. CONCLUSIONS In this large, modern series of cases performed in the sitting position, the complication rate was low. Suboccipital craniotomy/craniectomy was associated with the highest risk of complications. When appropriately used with modern anesthesia techniques, the sitting position provides a safe means of surgical access.

Study Design. Prospective cohort study. Objective. To characterize the accuracy of patient recollection of preoperative symptoms after lumbar spine surgery. Summary of Background Data. Although patient-reported outcomes have become important in the evaluation of spine surgery patients, the accuracy of patient recall remains unknown. Methods. Patients undergoing lumbar decompression with or without fusion were enrolled. Back and leg Numeric Pain Scores and Oswestry Disability Indices were recorded preoperatively. Patients were asked to recall their preoperative status at a minimum of 1 year after surgery. Actual and recalled scores were compared using paired t tests and relations were quantified using Pearson correlation coefficients. Multivariable linear regression was used to identify factors that affected recollection. Results. Sixty-two patients with a mean age of 66.1 years were included. Compared to their preoperative scores, patients showed significant improvement in back pain (mean difference [MD] = −3.2, 95% CI −4.0 to −2.4), leg pain (MD −3.3, 95% CI −4.3 to −2.2), and disability (MD −25.0%, 95% CI −28.7 to −19.6). Patient recollection of preoperative status was significantly more severe than actual for back pain (MD +2.3, 95% CI 1.5–3.2), leg pain (MD +1.8, 95% CI 0.9–2.7), and disability (MD +9.6%, 95% CI 5.6–14.0). No significant correlation between actual and recalled scores with regards to back (r = 0.18) or leg (r = 0.24) pain and only moderate correlation with disability (r = 0.44) were seen. This was maintained across age, sex, and time between date of surgery and recollection. More than 40% of patients switched their predominant symptom from back pain to leg pain or leg pain to back pain on recall. Conclusion. Relying on patient recollection does not provide an accurate measure of preoperative status after lumbar spine surgery. Recall bias indicates the importance of obtaining true baseline scores and patient-reported outcomes prospectively and not retrospectively. Level of Evidence: 2

Introduction Primary tumors of the spine requiring enbloc resection are rare. Most published reports are small and focus on disease free survival and recurrence rates. Very few studies focus on the various anterior and posterior reconstructive options and subsequent outcomes with respect to fusion rates and need for revision due to hardware failure. The objective of this review was to (1) summarize the published literature and (2) report the failure rates of various anterior and posterior reconstructive techniques after enbloc resection of spinal tumors and (3) supplement the deficiencies in the available published literature with expert opinion for reconstructive options from a group of experienced international spine tumor surgeons. Material and Methods An electronic search of the literature was undertaken from January 1990 – December 2013 evaluating specific reconstructive techniques of the spine after primary tumor enbloc resection. Prospective/retrospective trials and case series were included in the final analysis when fusion rates or failure rates were reported. The data available for each reconstructive technique was then combined and construct survivorship was summarized. In addition, a questionnaire was administered to a group of 20 international spine tumor surgeons evaluating specific reconstructive preferences at different regions of the spine based on the number of vertebrae resected and whether post-operative radiation was planned. Results The initial search yielded 381 articles with 31 subsequently included for full text review. Fourteen articles were included in the final analysis. There were 146 patients included for final review. There were 2/9 (22%) patients revised from short to long segment constructs and 3 reports of broken pedicle screws with only one requiring revision in longer constructs. Rates of revision for anterior reconstruction were similar for autogenous strut grafts (10%), cages (7.7%) and allograft strut grafts (8.3%). No surgeons responding to the questionnaire recommended short segment posterior constructs. For anterior reconstruction, cages packed with morcellized allograft and autograft were preferred (75%, p < 0.05) while strut bone grafting was choosen more often at the cervicothoracic junction (65%, p < 0.05) and when more than one vertebrae was resected in the mid thoracic spine (75%, p < 0.05). Few surgeons changed their anterior reconstructive technique (15%) or posterior reconstructive technique (10%) when post-operative radiation was planned. Conclusion The literature and consensus opinion supports posterior reconstruction with at least two vertebral levels of support above and below. For anterior vertebral column reconstruction, structural allograft, autograft and cages packed with morcelized bone have shown similar rates of fusion and failure. Expert opinion, however, suggests that structural autograft or potentially vascularized strut grafts should be used when spanning a defect greater than 2 vertebral bodies especially at the cervicothoracic junction.

Osteosarcoma is an aggressive primary bone tumor. It is currently treated with multimodality therapy including en bloc resection, which has been demonstrated to confer a survival benefit over intralesional resection. The authors present the case of an 8-year-old girl with a C-1 lateral mass osteosarcoma, which was treated with a 4-stage en bloc resection and spinal reconstruction. While technically complex, the feasibility of en bloc resection for spinal osteosarcoma should be explored in the pediatric population.

OBJECTIVE Primary spinal osteosarcomas are rare and aggressive neoplasms. Poor outcomes can occur, as obtaining marginal margins is technically demanding; further Enneking-appropriate en bloc resection can have significant morbidity. The goal of this study is to identify prognostic variables for local recurrence and mortality in surgically treated patients diagnosed with a primary osteosarcoma of the spine. METHODS A multicenter ambispective database of surgically treated patients with primary spine osteosarcomas was developed by AOSpine Knowledge Forum Tumor. Patient demographic, diagnosis, treatment, perioperative morbidity, local recurrence, and cross-sectional survival data were collected. Tumors were classified in 2 cohorts: Enneking appropriate (EA) and Enneking inappropriate (EI), as defined by pathology margin matching Enneking-recommended surgical margins. Prognostic variables were analyzed in reference to local recurrence and survival. RESULTS Between 1987 and 2012, 58 patients (32 female patients) underwent surgical treatment for primary spinal osteosarcoma. Patients were followed for a mean period of 3.5 ± 3.5 years (range 0.5 days to 14.3 years). The median survival for the entire cohort was 6.7 years postoperative. Twenty-four (41%) patients died, and 17 (30%) patients suffered a local recurrence, 10 (59%) of whom died. Twenty-nine (53%) patients underwent EA resection while 26 (47%) patients underwent EI resection with a postoperative median survival of 6.8 and 3.7 years, respectively (p = 0.048). EI patients had a higher rate of local recurrence than EA patients (p = 0.001). Patient age, previous surgery, biopsy type, tumor size, spine level, and chemotherapy timing did not significantly influence recurrence and survival. CONCLUSIONS Osteosarcoma of the spine presents a significant challenge, and most patients die in spite of aggressive surgery. There is a significant decrease in recurrence and an increase in survival with en bloc resection (EA) when compared with intralesional resection (EI). The effect of adjuvant and neoadjuvant chemotherapeutics, as well as method of biopsy, requires further exploration.

Study Design Retrospective study. Objective This study reviews 1,768 consecutive cervical decompressions with or without instrumented fusion to identify patient-specific and procedural risk factors significantly correlated with the development of delayed cervical palsy (DCP). Methods Baseline demographic and procedural information was collected from the electronic medical record. Particular attention was devoted to reviewing each chart for recognized risk factors of postsurgical inflammatory neuropathy: autoimmune disease, blood transfusions, diabetes, and smoking. Results Of 1,669 patients, 56 (3.4%) developed a DCP. Although 71% of the palsies involved C5, 55% of palsies were multimyotomal and 18% were bilateral. Significant risk factors on univariate analysis included age ( p = 0.0061, odds ratio [OR] = 1.07, 95% confidence interval [CI] 1.008 to 1.050), posterior instrumented fusion ( p < 0.0001, OR = 3.30, 95% CI 1.920 to 5.653), prone versus semisitting/sitting position ( p = 0.0036, OR = 3.58, 95% CI 1.451 to 11.881), number of operative levels ( p < 0.0001, OR = 1.42, 95% CI 1.247 to 1.605), intraoperative transfusions ( p = 0.0231, OR = 2.57, 95% CI 1.152 to 5.132), and nonspecific autoimmune disease ( p = 0.0107, OR = 3.83, 95% CI 1.418 to 8.730). On multivariate analysis, number of operative levels ( p = 0.0053, OR = 1.27, 95% CI 1.075 to 1.496) and nonspecific autoimmune disease ( p = 0.0416, OR 2.95, 95% CI 1.047 to 7.092) remained significant. Conclusions Although this study partially supports a mechanical etiology in the pathogenesis of a DCP, we also describe a notable correlation with autoimmune risk factors. Bilateral and multimyotomal involvement provides additional support that some DCPs may result from an inflammatory response and thus an underlying multifactorial etiology for this complication.

OBJECT A chordoma is an indolent primary spinal tumor that has devastating effects on the patient's life. These lesions are chemoresistant, resistant to conventional radiotherapy, and moderately sensitive to proton therapy; however, en bloc resection remains the preferred treatment for optimizing patient outcomes. While multiple small and largely retrospective studies have investigated the outcomes following en bloc resection of chordomas in the sacrum, there have been few large-scale studies on patients with chordomas of the mobile spine. The goal of this study was to review the outcomes of surgically treated patients with mobile spine chordomas at multiple international centers with respect to local recurrence and survival. This multiinstitutional retrospective study collected data between 1988 and 2012 about prognosis-predicting factors, including various clinical characteristics and surgical techniques for mobile spine chordoma. Tumors were classified according to the Enneking principles and analyzed in 2 treatment cohorts: Enneking-appropriate (EA) and Enneking-inappropriate (EI) cohorts. Patients were categorized as EA when the final pathological assessment of the margin matched the Enneking recommendation; otherwise, they were categorized as EI. METHODS Descriptive statistics were used to summarize the data (Student t-test, chi-square, and Fisher exact tests). Recurrence and survival data were analyzed using Kaplan-Meier survival curves, log-rank tests, and multivariate Cox proportional hazard modeling. RESULTS A total of 166 patients (55 female and 111 male patients) with mobile spine chordoma were included. The median patient follow-up was 2.6 years (range 1 day to 22.5 years). Fifty-eight (41%) patients were EA and 84 (59%) patients were EI. The type of biopsy (p < 0.001), spinal location (p = 0.018), and if the patient received adjuvant therapy (p < 0.001) were significantly different between the 2 cohorts. Overall, 58 (35%) patients developed local recurrence and 57 (34%) patients died. Median survival was 7.0 years postoperative: 8.4 years postoperative for EA patients and 6.4 years postoperative for EI patients (p = 0.023). The multivariate analysis showed that the EI cohort was significantly associated with an increased risk of local recurrence in comparison with the EA cohort (HR 7.02; 95% CI 2.96–16.6; p < 0.001), although no significant difference in survival was observed. CONCLUSIONS EA resection plays a major role in decreasing the risk for local recurrence in patients with chordoma of the mobile spine.

OBJECT Endoscopic approaches to the anterior craniocervical junction are increasing in frequency. Choice of oral versus endoscopic endonasal approach to the odontoid often depends on the relationship of the C1–2 complex to the hard palate. However, it is not known how this relevant anatomy changes with age. We hypothesize that there is a dynamic relationship of C-2 and the hard palate, which changes with age, and potentially affects the choice of surgical approach. The aim of this study was to characterize the relationship of C-2 relative to the hard palate with respect to age and sex. METHODS Emergency department billing and trauma records from 2008 to 2014 were reviewed for patients of all ages who underwent cervical or maxillofacial CT as part of a trauma evaluation for closed head injury. Patients who had a CT scan that allowed adequate visualization of the hard palate, opisthion, and upper cervical spine (C-1 and C-2) were included. Patients who had cervical or displaced facial/skull base fractures, a history of rheumatoid arthritis, or craniofacial anomalies were excluded. The distance from McGregor's palatooccipital line to the midpoint of the inferior endplate of C-2 (McL–C2) was measured on midsagittal CT scans. Patients were grouped by decile of age and by sex. A 1-way ANOVA was performed with each respective grouping. RESULTS Ultimately, 483 patients (29% female) were included. The mean age was 46 ± 24 years. The majority of patients studied were in the 2nd through 8th decades of life (85%). Significant variation was found between McL–C2 and decile of age (p < 0.001) and sex (p < 0.001). The mean McL–C2 was 27 mm in the 1st decade of life compared with the population mean of 37 mm. The mean McL–C2 was also noted to be smaller in females (mean difference 4.8 mm, p < 0.0001). Both decile of age (p = 0.0009) and sex (p < 0.0001) were independently correlated with McL–C2 on multivariate analysis. CONCLUSIONS The relationship of C-2 and the hard palate significantly varies with respect to age and sex, descending relative to the hard palate a full centimeter on average in adulthood. These findings may have relevance in determining optimal surgical approaches for addressing pathology involving the anterior craniocervical junction.